need help with tapping noise

my nephew has an 88 2.3 vert and we have done alot of misc. work, rear main, starter, battery, selenoid, fly wheel, etc. nothing to the actual engine and when we re-installed the tranny the other day and started it up I have a tapping noise in the engine compartment that wasn't there before is there any specific places I should start looking?

and where is a bad tap going to come from that could cause engine failure.

the car only has 130,000 on it and has run very well until that day.

btw we did all the work ourselves getting familiar with the car.


thanks
mike
 
update

I went to my nephews and listened to the engine and found that it is coming from uner the valve cover near the back of the engine.

suspects,

fouled plug, plug wires, cap and rotor.

would I be correct.

btw he's getting really crappy gas mileage too.

mike
 
You can do it in a couple of hours. I had to do my HLA's last summer, they ticked like a mofo. Dropped some new ones in and it quieted right down. Just make sure you have a better valvespring compressor than an 11/16" box end. ;)

Brian